Astrocytes as Metabolic Sensors Orchestrating Energy-Driven Brain Vulnerability in Alzheimer's Disease.

Alzheimer's disease (AD), the leading neurodegenerative disorder linked to aging, emerges within a paradoxical metabolic landscape. Despite rising cellular energy demands due to accumulated damage and stress, overall energy expenditure remains stable or declines with age. The brain, acting as the central regulator, responds to hypermetabolic signals from aged tissues by activating energy-conserving mechanisms. In this scenario, astrocytes, strategically located between blood vessels and neurons, play a pivotal role as energy sensors, adapting to systemic stress and modulating brain metabolism. This review explores how astrocytes undergo metabolic reprogramming in the early stages, potentially becoming maladaptive over time, fueling neuroinflammation, oxidative stress, and accelerating AD. By understanding astrocyte energetics, we uncover new avenues for biomarkers and therapies that could transform AD treatment.